Ring Opening of Cyclic Vinylogous Acyl Triflates Using Stabilized Carbanion Nucleophiles: Claisen Condensation Linked to Carbon−Carbon Bond Cleavage
作者:David M. Jones、Marilda P. Lisboa、Shin Kamijo、Gregory B. Dudley
DOI:10.1021/jo100249g
日期:2010.5.21
Addition of stabilized carbanionic nucleophiles to cyclic vinylogous acyl triflates (VATs) triggers a ring-opening fragmentation to give acyclic β-keto ester and related products, much like those observed traditionally in the Claisen condensation. Unlike in the classical Claisen condensation, however, the VAT-Claisen reaction described herein is rendered irreversible by C−C bond cleavage, not by deprotonation
Stereocontrolled synthesis of R or S diphenylphosphinoyl hydroxy aldehydes and 1,2 diols using bicyclic aminals
作者:Peter O'Brien、Stuart Warren
DOI:10.1016/0040-4039(95)00334-9
日期:1995.4
Homochiral diphenylphosphinoyl hydroxy aldehydes 1 and 2 have been made by diastereoselective additions of metallated methyldiphenylphosphine oxides 10 to Mukaiyama's keto aminals 8 and 9. Reduction to diphenylphosphinoyl 1,2 diols 3 and 4 is also described. Sharpless asymmetric dihydroxylation provides an alternative route to diphenylphosphinoyl 1,2 diols 3 and 4; the two approaches are compared.
Synthesis of phenylalanine-derived β-hydroxy and β-keto phosphine oxides — investigation of the configurational stability of lithiated phosphine oxides using the hoffmann test
作者:Peter O'Brien、Stuart Warren
DOI:10.1016/0040-4039(96)00814-3
日期:1996.6
Reaction between a phenylalanine-derived aldehyde and a lithiatedphosphineoxide (the Hoffmann test) has been used to demonstrate that lithiatedphosphineoxides are not configurationally stable in THF at −78 °C on the timescale of thier reaction with the aldehyde. Additionally, these reactions generate synthetically useful products.
Norephedrine-derived oxazolidines as chiral auxiliaries-stereocontrolled routes to R or S β-hydroxy phosphine oxides
作者:Peter O'Brien、Stuart Warren
DOI:10.1016/0040-4039(96)00467-4
日期:1996.4
Reduction of a β-keto phosphineoxideoxazolidine and reaction of an oxazolidine aldehyde with a lithiated phosphineoxide provide stereoselective routes to S or Rβ-hydroxyphosphineoxides.